Politically conservative Americans have lost trust in science over the last 40 years while moderates and liberals have remained constant in the stock they put in the scientific community, a new study finds.

The most educated conservatives have slipped the most, according to the research set to appear in the April issue of the journal American Sociological Review. The change in conservative attitudes likely has to do both with changes in the conservative movement and with changes in science's role in society, said study author Gordon Gaulet, a postdoctoral researcher at the University of North Carolina, Chapel Hill.

"There's been this need to cultivate conservative ideas in reaction to what is perceived as mainstream culture, which a lot of conservatives would suggest is biased toward secular liberalism," Gaulet told LiveScience. "Part of what being a conservative means is looking for alternatives for mainstream ideas and bases of knowledge, and science and the media are those." [Life's Extremes: Democrats & Republicans]

Science and politics

The trouble with assessing the public's opinion of science over time is that few public opinion polls asked questions about trust in science before the 1980s. One major survey, the General Social Survey, did ask Americans about their trust in the scientific community starting in 1974, however.

Gaulet used this survey, which was conducted annually until 1994 and every other year through 2010, to gauge changes in different groups' trust in science over time. He found that overall, trust in science is not especially high — fewer than half of Americans surveyed over the time frame reported a "great deal" of trust in the scientific community.

Liberals had the most trust in science as a whole over the survey period (1974 to 2010), with 47 percent reporting a "great deal" of trust on average, while moderates were the most consistently skeptical of science, with 42 percent trusting the scientific community a great deal. (The moderates in the survey tended to have the least understanding of science as any group, possibly explaining the finding, Gaulet said.) An average of 43 percent of conservatives said they trusted scientists a great deal over the study period.

But only conservatives showed a change over time. At the beginning of the survey, in the 1970s, conservatives trusted science more than anyone, with about 48 percent evincing a great deal of trust. By 2010, the last year survey data was available, only 35 percent of conservatives said the same.

What's changed?

Gaulet said that conservatism itself has changed, with a greater emphasis on conservative thought and think tanks such as The Heritage Foundation that make a point of challenging the scientific community. The finding wasn't the result of conservatives being less educated than in the old days, he said. In fact, the decline in trust was most obvious among conservatives with a bachelor's degree or higher. [The World's Greatest Minds]

Meanwhile, science has changed, too. Research used to be done under the auspices of NASA and the Department of Defense, Gaulet said. Both of these agencies seemed far-removed from daily life. However, over the decades, science has become more intertwined with everyday policy. The Environmental Protection Agency is a "poster child" for science informing real-world regulation that some conservatives oppose, Gaulet said.

"It's almost a contradiction," he said. "We use science because it has this objective point of view or credibility to figure out which policy to use ... but by doing that it becomes politicized."

Interestingly, public opinion on science in Europe and Japan skews differently than in the United States, Gaulet said. There, skepticism about the scientific community usually comes from the left. The reason may be that the issues on the scientific forefront in Europe (genetically modified food, nuclear power) tend to push liberals' buttons, while those in the United States (climate change, stem cell research) tend to bother conservatives more.

Gaulet doesn't favor pulling science out of the public sphere, in fact preferring that scientists be even more outspoken about their research. But they should be prepared for pushback.

"I think this is the new reality," he said. "If we want science to be a major part of our culture, and our political culture, then [politicization] is going to be a potential problem."